Comet C/2011 W3 Lovejoy is a comet on its way to the outer solar system. It survived a close brush with the sun in December 2011. It is one of four comets discovered by amateur astronomer Terry Lovejoy.

The Sombrero Galaxy, also called M104 or NGC 4594, is about 28 million light-years from our planet in the constellation Virgo. It is so named because the halo surrounding its disc is unusually large, making it look like a sombrero.

The Hubble Constant is the unit of measurement used to describe the expansion of the universe. The cosmos has been getting bigger since the Big Bang kick-started the growth about 13.82 billion years ago.

Gravitational waves are the "smoking gun" of the Big Bang. Predicted by Albert Einstein's theory of general relativity in 1916, a massive object like Earth distorts space-time around it like a bowling ball dropped on a trampoline.

Edmond Halley is best remembered for predicting the orbit of the comet that was later named after him. Besides astronomy, he also made significant discoveries in the fields of geophysics, mathematics, meteorology and physics.